Laser‐Assisted Delamination for High‐Value Recycling of Solar Panels

ABSTRACT With the increasingly large volumes of silicon solar panels being decommissioned worldwide, we urgently need to come up with a cheap and efficient recycling strategy that yields high‐value output materials. A crucial step in such recycling is to delaminate the front and back sheets to access the cells and their metallization. In this work, we demonstrate that the adhesion between the encapsulant and the silicon wafers can be weakened, in a fast and effective way, using a picosecond pulsed near‐infrared laser. The glass and encapsulant are then delaminated from the silicon wafer in a thermomechanical step. This method provides direct access to the silicon emitter and bulk as well as the precious and/or toxic metals on its surface, enabling their recycling. Ablation threshold experiments show that the IR laser mostly interacts with the silicon, thereby indirectly ablating the SiN x anti‐reflective coating. We show that laser pattern and laser setting optimization help strike a balance between effective silicon wafer surface ablation and minimal (submicron thick) contamination from the encapsulant, due to lower heat dissipation into the wafer and encapsulant. The SiN x removal, combined with high potential throughput and low OpEx, sets this process apart from existing delamination techniques. The process described in this paper can be crucial to enable rapid and energy‐efficient recycling of silicon PV modules to high‐purity raw materials with a high recovery rate.